This invention relates to a method of lining a high-pressure pipe with a tube formed from interlocking, high-tensile high-performance fibers and a plastic coating applied to the fibers, and the construction of such a tube.
The invention relates to a method according to the preamble of claim 1 as well as a tube according to the preamble of claim 6.
High-pressure pipes transport fluid media at a pressure in the range of more than 1 bar. The pipes must therefore withstand correspondingly high forces and be of adequate dimensions. For the tubes, therefore, so-called high-performance fibres are used which have a high tearing strength and are relatively high-tensile. From the viewpoint of increasing the strength, these fibres are most effective when they run perpendicular to the longitudinal axis of the pipe or tube. The fabrics of the known tubes are so configured that they consist of warp and weft threads which run in the longitudinal direction of the tube or respectively perpendicular to same. These tubes, however, have only low tensibility in a radial direction. This tensibility is not sufficient, however, to compensate for production tolerances of the pipes and the tubes. Since maximum tolerances of the pipes and the tubes of roughly 3% in each case have to be taken into account, a tube of this type should have a tensibility of not less than 6%.
The previous renovation tubes for high-pressure pipes have, as mentioned above, a fabric formed from warp and weft threads, the warp threads running in the longitudinal direction of the pipe.
The object of the present invention, therefore, is to give a method for lining a high-pressure pipe with a tube formed from interlocking, high-tensile high-performance fibres and a plastics coating applied to said fibres, as well as a tube of this type, which despite high strength in a radial direction and also in an axial direction permit a maximum radial enlargement of the tube to at least 3% above the nominal diameter of the pipe.
This object is accomplished according to the present invention by arranging the high-performance fibers in a braided or meshing structure that is introduced into the pipe with the fibers in a state of mobility relative to one another so that the introduced meshing is positioned against the inner wall of the pipe by altering the geometrical arrangement of the high-performance fibers in relation to one another. The mutual arrangement of the high-performance fibers is then fixed in the position that they have assumed as a result of the positioning of the fibers against the pipe inner wall. The tube structure that will permit this operation is a braided structure wherein the high-performance fibers are angled in relation to the perpendicular to the tube axis before lining so that during the lining operation the tube can be enlarged in a radial direction.
Since the high-performance fibres are arranged in a braided structure and are introduced into the pipe in a state of mobility relative to one another, and since the introduced meshing is laid against the inner wall of the pipe by altering the geometrical arrangement of the high-performance fibres in relation to one another and these fibres are then fixed in their relative position assumed after they have been laid, the tube can, as it is laid against the inner wall of the pipe, be so enlarged in a radial direction practically without any force, that production tolerances or otherwise caused fluctuations of the inside diameter of the pipe can be compensated without the high-performance fibres themselves being stretched.